This invention relates to environmental control systems that supply to a conditioned space a constant volume of heated or cooled air with respect to system variables and a variable volume with respect to space heating or cooling demands.
There are a number of prior art control systems that use system pressure changes to reposition dampers or the like to effect a change in the orifice size for adjusting the rate of flow. These prior art control systems use open loop control which are incapable of determining whether the amount of correction is adequate.
One object of this invention is to provide in an environmental control system a closed loop air distribution system that is powered from system pressure to regulate the flow rate into the conditioned space.
Another object of this invention is to provide in a pressurized environmental air distribution system a novel pressure regulating valve that controls the pressure drop across a given impedance to regulate the flow rate.
Still another object of this invention is to provide a closed loop air distribution control system that utilizes a novel pressure regulating valve to regulate the flow rate in proportion to changes in environmental temperature.
A further object of this invention is to provide an air distribution control system that uses a pressure regulating valve to regulate the flow rate of one air supply at a certain temperature in response to changes in environmental temperature, a second mechanically-set pressure regulating valve to regulate the flow rate of a second air supply at a different temperature, and a plenum chamber to mix the two air supplies and provide a constant volume to the conditioned space.
A still further object of this invention is to provide an environmental air distribution control system having a plurality of outlets that utilizes at each outlet a pressure regulating valve for adjusting the flow rate of each outlet.